When I built the Simucube direct-drive wheel to replace my Fanatec CSW v2, I used Bluetooth as a temporary solution to get the paddle shifters working, but what about a permanent solution? And getting the rest of the buttons and LEDs to work?!  Enter the Bodnar-Fanatec USB Conversion PCB…

When I disassembled the steering wheel, I noticed a bad soldering job on the circuit board — pins 3 and 4 are lumped together.  🙁

Oops! Bad soldering at the Fanatec factory.

Fixed! Thank you solder wick.

Step 1:  Add Pins to the Bodnar PCB

My goal here was to make it so that I could return the Fanatec Formula Rim to factory condition, in case I ever upgrade the wheel or decide to sell it.  Bodnar does sell a solderless version of the board, what what fun would that be?!  So, step 1 was to add some pins to the Bodnar PCB so I could connect some cabling.

Bodnar board with pins soldered for top, bottom, and USB. Be warned, he top pins are a smaller spacing than the USB and bottom pins.

Step 2:  Fix Connecting Wires to the Bodnar PCB

I used a couple off-the-shelf components for wiring, plus some simple 1-pin wires I had laying around.  Unfortunately, I can’t remember the specs on the 8-pin connector (smaller, closer pins than the bottom and USB connections).

Using an off-the-shelf USB connector

Apologies for the blurry photo, not sure what happened there.

Wires connected and a little hot glue to keep things from shaking loose

Step 3:  Fix Connecting Wires to the Fanatec PCB

I used some 1-pin jumper wires for the 6-pins at the bottom of the board. For fit and finish, would be nice to find a 6-pin connector, but the biggest I had in my spare parts bin was for 5-pins.

6 wires connected and hot-glued in place

Careful, make sure that the correct pins are connected

Step 3:  Re-assemble and Test

My 70mm-52mm adapter is too big and prevents re-installation of the plastic covers.  The  bottom one would be nice because then I could put a bung in and that would make the USB connection cleaner.  Instead, (not pictured) I passed an electric tie thru one of the spare bolt holes to cinch it into place and prevent stress on the wires & pins.

Reassembled, could be a bit tidier, but not bad

Suppliers:

• Bodnar-Fanatec USB Conversion PCB: http://www.leobodnar.com/shop/index.php?main_page=product_info&products_id=236

Looks like it was made to go there, no?!

Ready for a drive?

Pretty much just four screws.  The modifications mean that I can’t replace the plastic pieces that covered the top and bottom of the rim, so the Fanatec circuit board is visible. C’est la vie…

Can you see the power circuit board just barely peeking out?

And, oh, you can finally see the 52-70mm adaptor and how it squeezes in between the paddle shifters.

There’s the bluetooth module

NOTE:  The coin cell battery only had enough juice for 30-60 minutes of shifting and the last bit of that was flaky,  I switched this out for a 3xAAA battery array, which worked much better.

I didn’t show it in the soldering section, but I also prepped a 20mm coin-cell battery as the power module. There’s a tiny on/off switch, but in practice I think it will be much easier just to remove the battery.  Also, I didn’t solder the wires to the circuit boards because this is a temporary setup. I will be upgrading soon enough to a Leo Bodnar board that will get all the buttons on the F1 rim working, not just the paddle shifters!

Using a little foam tape to mount the circuit boards

With both circuit boards in place, the wiring gets a little cramped.

Both circuit boards in place

A second angle

See the antenna?  Placed the circuit board high enough on the mounting brace so that the antenna portion of the circuit board is above the metal, just to minimize possible interference issues with the bluetooth signal.

And finally, a little electrical tape to help keep things under control.

A real DIYer would use duck tape, not electrical tape!

Check out (or don’t!) my soldering skills.  If you do you’ll notice that:

• I didn’t clean off the flux before taking pictures
• There are one or two places where the board got a little too hot
• There are a couple cold solders (blobby, not cones)
• There is nothing fatally wrong with any of my solder joints  🙂

Soldered from the other side, so this is flow-thru

The opposite bank of pins

View from the soldered side

And again, the opposite bank of pins

To disassemble I followed the steps in this very nice YouTube video:

This is the dis-assembled Fanatec F1 Rim. There were a couple of tricky points, especially disconnecting the 8-pin connector from the circuit board. It was hot-glued in place, so had to carefully cut around the connector with a razor knife and remove the glue. Easy enough, a little care and don’t press too hard, hot glue is pretty easy to cut thru.

Torn-down Fanatec F1 rim, mounting assembly and quick release gone

For the sake of completeness, you can see where the quick release mounted.  Also, note the wiring from the paddle shifters, these make it very easy to connect via bluetooth (steps 4 and 5). In Fanatec’s world, the connectors you see here plug into the circuit board attached to the steering wheel. In my new version, they will attach to a bluetooth board. 🙂

Quick release removed from mounting bracket

Here’s the Fanatec mounting bracket with shifter paddles attached.  Important thing here is that the Fanatec bolt circle is 52mm, so will need an adapter to mate to the 70mm attached to the Mige.

Bare Fanatec mounting plate

Took a picture from the wrong side.  Doh!  But this is with the 52mm-70mm adaptor attached.  I bought the adapter from Steve Spenceley, simracingengineering@gmail.com.  I found Steve on Shapeways, http://www.shapeways.com/product/A8X7BZD68/fanatec-52mm-to-70mm-adapter.  I was thinking about trying to CNC my own, but this was way faster and easier.

52-70mm adaptor attached

As you can see, the adapter is square, not round. That’s not a problem, but it was a tight fit between the paddle shifters.  If I were going to do it again, I would want to trim this down a little bit, there are several millimeters of material that can be taken off all sides.  A round one would also be more aesthetically pleasing.  The other optimization is that this adaptor and the wood spacer I built could be one piece.

Here’s an alternate view that also shows some empty space, which is where I will stuff some electronics to make the paddle shifters work.  🙂

Fanatec F1 rim with 52-70mm adaptor installed

There are a handful of motors that will work, with the Kollmorgen highest rated amongst them, but also hard to acquire and quite expensive by comparison.  The inexpensive options are the Chinese-made Mige motors.  The so-called “small Mige” has a lower power rating, so produces less force on the wheel.  If my experiments to date are any indication, that additional force is not needed.  😮

The “small Mige” is both quite heavy and quite powerful.

There is a compression fit coupling that provides the platform to which the wheel or quick release is attached.  The Simucube kit from SimRacing Bay included the 6-pointed star-shaped 70mm adaptor seen in the images.  The 4 bolts in the center clamp the coupling to the shaft.

Small Mige with 70mm adaptor and shaft coupling attached

But, since they stick out further than the surface of the 70mm adaptor plate, I needed to make a small spacer about 5/16 thick to prevent interference with my steering wheel mount.  Found some scrap wood and used a 3 1/4 and a 2 1/8 circular drill bits to create the spacer.

Spacer I created out of some scrap wood

Didn’t take very many pictures at this stage. Relatively simple process to assemble the components from the Simucube kit, toughest decision was whether to use the crimp-on connectors supplied or to solder the wires to the power input.

The case is acrylic, snaps together Lego-like, there was some minor filing of a few of the tabs to get everything to fit smoothly.

The tiny, supplied fan is too noisy.  A necessary upgrade is to figure out how to stuff a 120mm fan in this box.

Simucube Innards

An ever-expanding project to build a direct drive steering wheel for Sim Racing, originally inspired by the OSW (Open Sim Wheel) project and accelerated by the Indiegogo campaign for the Simucube.

1. Simucube
2. The Small Mige
3. Modifying a Fanatec Formula Rim
4. Soldering Up a Bluefruit Circuit Board
5. Wiring Paddle Shifters to the Bluetooth Module
6. Re-assembling the Fanatec Formula Steering Wheel
7. Rim, meet Mige; Mige, meet Rim

Suppliers:

• Simucube:  https://granitedevices.com/simucube-simulator-force-feedback-controller/
• Wiring & Other accessories:   http://www.simracingbay.com/product/mige-osw-kit/
• Adaptor(s):  Steve Spenceley, simracingengineering@gmail.com
• Bluefruit Bluetooth Module:  www.adafruit.com